As the value and use of information continues to increase, individuals and businesses seek additional ways to process and store information. One option available to users is information handling systems. An information handling system generally processes, compiles, stores, and/or communicates information or data for business, personal, or other purposes thereby allowing users to take advantage of the value of the information. Because technology and information handling needs and requirements vary between different users or applications, information handling systems may also vary regarding what information is handled, how the information is handled, how much information is processed, stored, or communicated, and how quickly and efficiently the information may be processed, stored, or communicated. The variations in information handling systems allow for information handling systems to be general or configured for a specific user or specific use such as financial transaction processing, airline reservations, enterprise data storage, or global communications. In addition, information handling systems may include a variety of hardware and software components that may be configured to process, store, and communicate information and may include one or more computer systems, data storage systems, and networking systems.
As processors, graphics cards, random access memory (RAM) and other components in information handling systems have increased in clock speed and power consumption, the amount of heat produced by such components as a side-effect of normal operation has also increased. Often, the temperatures of these components need to be kept within a reasonable range to prevent overheating, instability, malfunction and damage leading to a shortened component lifespan. Accordingly, air movers (e.g., cooling fans and blowers) have often been used in information handling systems to cool information handling systems and their components.
Often, the operation of an air mover (e.g., rotational speed of air movers) is controlled by a proportional-integral-differential (PID) closed-loop control system. Typical PID closed-loop control is based on a mathematical equation summing proportional, integral, and differential terms of the variable (e.g., air mover speed) being controlled. Traditional PID control implementations are prone to oscillation and excessive lag if not tuned correctly. Oscillation occurs when a PID controller repeatedly makes changes that are too large and repeatedly overshoots a target variable setpoint, meaning that a system output would oscillate around the setpoint in either a constant, growing, or decaying sinusoid. If the oscillations increase with time then the system is unstable, whereas if they decrease the system is stable. If the oscillations remain at a constant magnitude the system is marginally stable. When PID control is used to control an air mover, oscillation may be audibly noticeable to an end user.
Lag occurs when a significant change in a setpoint for a PID controller occurs, and the PID controller requires significant time to correct the system output to match the new set point. When used to control operation of an air mover, PID control may not respond quickly enough to prevent undesirable thermal increases.
In addition to these disadvantages of PID control as applied to control of air movers, such disadvantages may also be present in other applications of PID control.